firmware/target/arm/imx31/gigabeat-s/button-imx31.c

   1 /***************************************************************************
   2  *             __________               __   ___.
   3  *   Open      \______   \ ____   ____ |  | _\_ |__   _______  ___
   4  *   Source     |       _//  _ \_/ ___\|  |/ /| __ \ /  _ \  \/  /
   5  *   Jukebox    |    |   (  <_> )  \___|    < | \_\ (  <_> > <  <
   6  *   Firmware   |____|_  /\____/ \___  >__|_ \|___  /\____/__/\_ \
   7  *                     \/            \/     \/    \/            \/
   8  * $Id$
   9  *
  10  * Copyright (C) 2006 by Linus Nielsen Feltzing
  11  *
  12  * This program is free software; you can redistribute it and/or
  13  * modify it under the terms of the GNU General Public License
  14  * as published by the Free Software Foundation; either version 2
  15  * of the License, or (at your option) any later version.
  16  *
  17  * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
  18  * KIND, either express or implied.
  19  *
  20  ****************************************************************************/
  21
  22 #include "config.h"
  23 #include "cpu.h"
  24 #include "system.h"
  25 #include "button.h"
  26 #include "backlight.h"
  27 #include "backlight-target.h"
  28 #include "avic-imx31.h"
  29 #include "ccm-imx31.h"
  30 #include "mc13783.h"
  31
  32 /* Most code in here is taken from the Linux BSP provided by Freescale
  33  * Copyright 2004-2006 Freescale Semiconductor, Inc. All Rights Reserved. */
  34 static uint32_t int_btn     = BUTTON_NONE;
  35 static bool hold_button     = false;
  36 #ifdef BOOTLOADER
  37 static bool initialized     = false;
  38 #else
  39 static bool hold_button_old = false;
  40 #endif
  41 #define _button_hold() (GPIO3_DR & 0x10)
  42
  43 static __attribute__((interrupt("IRQ"))) void KPP_HANDLER(void)
  44 {
  45     static const struct key_mask_shift
  46     {
  47         uint8_t mask;
  48         uint8_t shift;
  49     } kms[3] =
  50     {
  51         { 0x1f, 0 }, /* BUTTON_LEFT...BUTTON_SELECT */
  52         { 0x03, 5 }, /* BUTTON_BACK...BUTTON_MENU   */
  53         { 0x1f, 7 }, /* BUTTON_VOL_UP...BUTTON_NEXT */
  54     };
  55
  56     int col;
  57     /* Power button is handled separately on PMIC, remote read in headphone
  58      * jack driver. */
  59 #ifdef HAVE_HEADPHONE_DETECTION
  60     int button = int_btn & (BUTTON_POWER | BUTTON_REMOTE);
  61 #else
  62     int button = int_btn & BUTTON_POWER;
  63 #endif
  64
  65     int oldlevel = disable_irq_save();
  66
  67     /* 1. Disable both (depress and release) keypad interrupts. */
  68     KPP_KPSR &= ~(KPP_KPSR_KRIE | KPP_KPSR_KDIE);
  69
  70     for (col = 0; col < 3; col++) /* Col */
  71     {
  72         /* 2. Write 1s to KPDR[10:8] setting column data to 1s */
  73         KPP_KPDR |= (0x7 << 8);
  74
  75         /* 3. Configure columns as totem pole outputs(for quick
  76          * discharging of keypad capacitance) */
  77         KPP_KPCR &= ~(0x7 << 8);
  78
  79         /* Give the columns time to discharge */
  80         udelay(2);
  81
  82         /* 4. Configure columns as open-drain */
  83         KPP_KPCR |= (0x7 << 8);
  84
  85         /* 5. Write a single column to 0, others to 1.
  86          * 6. Sample row inputs and save data. Multiple key presses
  87          *    can be detected on a single column.
  88          * 7. Repeat steps 2 - 6 for remaining columns. */
  89
  90         /* Col bit starts at 8th bit in KPDR */
  91         KPP_KPDR &= ~(0x100 << col);
  92
  93         /* Delay added to avoid propagating the 0 from column to row
  94          * when scanning. */
  95         udelay(2);
  96
  97         /* Read row input */
  98         button |= (~KPP_KPDR & kms[col].mask) << kms[col].shift;
  99     }
 100
 101     /* 8. Return all columns to 0 in preparation for standby mode. */
 102     KPP_KPDR &= ~(0x7 << 8);
 103
 104     /* 9. Clear KPKD and KPKR status bit(s) by writing to a .1.,
 105      *    set the KPKR synchronizer chain by writing "1" to KRSS register,
 106      *    clear the KPKD synchronizer chain by writing "1" to KDSC register */
 107     KPP_KPSR = KPP_KPSR_KRSS | KPP_KPSR_KDSC | KPP_KPSR_KPKR | KPP_KPSR_KPKD;
 108
 109     /* 10. Re-enable the appropriate keypad interrupt(s) so that the KDIE
 110      *     detects a key hold condition, or the KRIE detects a key-release
 111      *     event. */
 112     if ((button & ~BUTTON_POWER) != BUTTON_NONE)
 113         KPP_KPSR |= KPP_KPSR_KRIE;
 114     else
 115         KPP_KPSR |= KPP_KPSR_KDIE;
 116
 117     int_btn = button;
 118
 119     restore_irq(oldlevel);
 120 }
 121
 122 bool button_hold(void)
 123 {
 124     return _button_hold();
 125 }
 126
 127 #ifdef HAVE_HEADPHONE_DETECTION
 128 /* Headphone driver pushes the data here */
 129 void button_headphone_set(int button)
 130 {
 131     int oldstatus = disable_irq_save();
 132     int_btn = (int_btn & ~BUTTON_REMOTE) | button;
 133     restore_irq(oldstatus);
 134 }
 135 #endif
 136
 137 int button_read_device(void)
 138 {
 139     /* Simple poll of GPIO status */
 140     hold_button = _button_hold();
 141
 142 #ifndef BOOTLOADER
 143     /* Backlight hold handling */
 144     if (hold_button != hold_button_old)
 145     {
 146         hold_button_old = hold_button;
 147         backlight_hold_changed(hold_button);
 148     }
 149 #endif
 150
 151     /* Enable the keypad interrupt to cause it to fire if a key is down.
 152      * KPP_HANDLER will clear and disable it after the scan. If no key
 153      * is depressed then this bit will already be set in waiting for the
 154      * first key down event. */
 155     KPP_KPSR |= KPP_KPSR_KDIE;
 156
 157 #ifdef HAVE_HEADPHONE_DETECTION
 158     /* If hold, ignore any pressed button. Remote has its own hold
 159      * switch, so return state regardless. */
 160     return hold_button ? (int_btn & BUTTON_REMOTE) : int_btn;
 161 #else
 162     /* If hold, ignore any pressed button.  */
 163     return hold_button ? BUTTON_NONE : int_btn;
 164 #endif
 165 }
 166
 167 /* This is called from the mc13783 interrupt thread */
 168 void button_power_event(void)
 169 {
 170     bool pressed =
 171         (mc13783_read(MC13783_INTERRUPT_SENSE1) & MC13783_ONOFD1S) == 0;
 172
 173     /* Prevent KPP_HANDLER from changing things */
 174     int oldlevel = disable_irq_save();
 175
 176     if (pressed)
 177     {
 178         int_btn |= BUTTON_POWER;
 179     }
 180     else
 181     {
 182         int_btn &= ~BUTTON_POWER;
 183     }
 184
 185     restore_irq(oldlevel);
 186 }
 187
 188 void button_init_device(void)
 189 {
 190 #ifdef BOOTLOADER
 191     /* Can be called more than once in the bootloader */
 192     if (initialized)
 193         return;
 194
 195     initialized = true;
 196 #endif
 197
 198     /* Enable keypad clock */
 199     ccm_module_clock_gating(CG_KPP, CGM_ON_RUN_WAIT);
 200
 201     /* 1. Enable number of rows in keypad (KPCR[4:0])
 202      *
 203      * Configure the rows/cols in KPP
 204      * LSB nybble in KPP is for 5 rows
 205      * MSB nybble in KPP is for 3 cols */
 206     KPP_KPCR |= 0x1f;
 207
 208     /* 2. Write 0's to KPDR[10:8] */
 209     KPP_KPDR &= ~(0x7 << 8);
 210
 211     /* 3. Configure the keypad columns as open-drain (KPCR[10:8]). */
 212     KPP_KPCR |= (0x7 << 8);
 213
 214     /* 4. Configure columns as output, rows as input (KDDR[10:8,4:0]) */
 215     KPP_KDDR = (KPP_KDDR | (0x7 << 8)) & ~0x1f;
 216
 217     /* 5. Clear the KPKD Status Flag and Synchronizer chain.
 218      * 6. Set the KDIE control bit bit. */
 219     KPP_KPSR = KPP_KPSR_KDIE | KPP_KPSR_KRSS | KPP_KPSR_KDSC | KPP_KPSR_KPKD;
 220
 221     avic_enable_int(INT_KPP, INT_TYPE_IRQ, INT_PRIO_DEFAULT, KPP_HANDLER);
 222
 223     button_power_event();
 224     mc13783_enable_event(MC13783_ONOFD1_EVENT);
 225
 226 #ifdef HAVE_HEADPHONE_DETECTION
 227     headphone_init();
 228 #endif
 229 }
 230
 231 #ifdef BUTTON_DRIVER_CLOSE
 232 void button_close_device(void)
 233 {
 234     int oldlevel = disable_irq_save();
 235
 236     avic_disable_int(INT_KPP);
 237     KPP_KPSR &= ~(KPP_KPSR_KRIE | KPP_KPSR_KDIE);
 238     int_btn = BUTTON_NONE;
 239
 240     restore_irq(oldlevel);
 241 }
 242 #endif /* BUTTON_DRIVER_CLOSE */